U.S. patent number 5,478,705 [Application Number 08/248,925] was granted by the patent office on 1995-12-26 for milling a compound useful in imaging elements using polymeric milling media.
This patent grant is currently assigned to Eastman Kodak Company. Invention is credited to James R. Bennett, John F. Bishop, David A. Czekai, Dennis E. Smith, Paul E. Woodgate.
United States Patent |
5,478,705 |
Czekai , et al. |
December 26, 1995 |
Milling a compound useful in imaging elements using polymeric
milling media
Abstract
Particles of compound useful in imaging elements are milled
using a milling media comprising a polymeric resin. The use of
polymeric milling media permits the production of particles having
an average particle size less than 1 micron. Further, the resulting
particles are free from the contamination resulting from
conventional milling media of, for example, glass, ceramic or
steel.
Inventors: |
Czekai; David A. (Honeoye
Falls, NY), Smith; Dennis E. (Rochester, NY), Bishop;
John F. (Rochester, NY), Woodgate; Paul E. (Spencerport,
NY), Bennett; James R. (Rochester, NY) |
Assignee: |
Eastman Kodak Company
(Rochester, NY)
|
Family
ID: |
22941287 |
Appl.
No.: |
08/248,925 |
Filed: |
May 25, 1994 |
Current U.S.
Class: |
430/449; 241/184;
430/349; 430/377; 430/546; 430/631 |
Current CPC
Class: |
B41M
5/38207 (20130101); C09B 67/0002 (20130101); G03C
1/005 (20130101); G03G 5/09 (20130101) |
Current International
Class: |
C09B
67/00 (20060101); C09B 67/04 (20060101); G03G
5/04 (20060101); G03C 1/005 (20060101); G03G
5/09 (20060101); B02C 017/20 () |
Field of
Search: |
;430/546,377,449,631
;241/184 |
References Cited
[Referenced By]
U.S. Patent Documents
|
|
|
3104608 |
September 1963 |
Castelll et al. |
3713593 |
January 1973 |
Morris et al. |
4262851 |
April 1981 |
Graser et al. |
4404346 |
September 1983 |
Pirotta et al. |
4474872 |
October 1984 |
Onishi et al. |
4940654 |
July 1990 |
Diehl et al. |
4974368 |
December 1990 |
Miyamoto et al. |
5066335 |
November 1991 |
Lane et al. |
5066486 |
November 1991 |
Kamen et al. |
5145684 |
September 1992 |
Liversidge et al. |
|
Foreign Patent Documents
Other References
Drukenbrod, "Smaller Is Better?", Paint & Coatings Industry,
Dec. 1991, p. 18..
|
Primary Examiner: Bowers, Jr.; Charles L.
Assistant Examiner: Huff; Mark F.
Attorney, Agent or Firm: Anderson; Andrew J.
Claims
What is claimed is:
1. A process for the preparation of solid particles of a compound
useful in photographic, electrophotographic, or thermal transfer
imaging elements having an average particle size of less than 1
micron selected from the group consisting of dye-forming couplers,
development inhibitor release couplers (DIR's), development
inhibitor anchimeric release couplers (DI(A)R's), masking couplers,
filter dyes, thermal transfer dyes, optical brighteners,
nucleators, development accelerators, oxidized developer
scavengers, ultraviolet radiation absorbing compounds, sensitizing
dyes, development inhibitors, antifoggants, bleach accelerators,
magnetic particles, lubricants, and matting agents, which comprises
milling said compound in the presence of milling media comprising a
polymeric resin.
2. A process according to claim 1, wherein milling media consists
essentially of a polymeric resin.
3. A process according to claim 1, wherein the milling media
consists essentially of a core having adhered thereon a coating of
said polymeric resin.
4. A process according to claim 1, wherein the polymeric resin is
selected from the group consisting of cross linked polystyrenes,
styrene copolymers, polycarbonates, polyacetals, vinyl chloride
polymers and copolymers, polyurethanes, polyamides, fluoropolymers,
high density polyethylenes, polypropylenes, cellulose ethers and
esters, polyacrylates and silicone containing polymers.
5. A process according to claim 4, wherein the polymeric resin is
polystyrene cross linked with divinyl benzene.
6. A process according to claim 4, wherein the polymeric resin is a
polycarbonate.
7. A process of claim 1, wherein said milling media has an average
size of 0.1-3 mm.
8. A process according to claim 1, wherein the compound useful in
imaging elements is milled in a liquid medium.
9. A process according to claim 1, wherein the milling takes place
in a mill selected from the group consisting of an airjet mill, a
roller mill, a ball mill, a media mill an attritor mill a vibratory
mill, a planetary mill, a sand mill, and a bead mill.
10. A process according to claim 9, wherein the mill is a high
energy media mill.
11. A process according to claim 1, wherein the compound is a
filter dye, a thermal transfer dye, or a sensitizing dye.
12. A process according to claim 11, wherein the compound useful in
imaging elements is a filter dye.
13. A process according to claim 1, wherein the particles have an
average particle size of less than about 500 nanometers.
Description
FIELD OF THE INVENTION
This invention relates to a process for producing fine particles of
a compound useful in imaging elements and to dispersions of such
compounds.
BACKGROUND OF THE INVENTION
Comminution (size reduction by mechanical means) of crystalline
solids using wet milling techniques such as ball milling or media
milling processes is a common technique used in the paint and
pigment industry and has recently been exploited for producing
small (<1 .mu.m) size particle dispersions of photographic
materials, for example, see U.S. Pat. No. 4,940,654 to Diehl et al.
In such milling applications, milling media are generally selected
from a variety of dense materials, such as steel, ceramic or glass.
In ball milling processes, both milling efficiency and
attrition-related contamination are generally thought to be
proportional to media density. Higher viscosity dispersions often
require very dense media, such as stainless steel. Media geometries
may vary depending on the application, although spherical or
cylindrical beads are most commonly used.
Dispersions prepared by these techniques are typically stabilized
using a surface agent to prevent agglomeration. In general, it is
desirable to obtain the smallest possible particle size while
minimizing attrition-related contamination from milling equipment
and milling media. Such goals are often contradictory, i.e., the
increased energy required to achieve a small particle size often
results in excessive levels of metallic, ceramic or other types of
contamination. High intensity milling is also desirable to maximize
milling efficiencies, (i.e., rate of size reduction).
Attrition-related contamination in compounds useful in imaging
elements dispersions (filter dyes, sensitizing dyes, couplers,
antifoggants, etc.) can result in both physical and sensitometric
defects. Contamination resulting from the milling process is
usually present in the form of dissolved species or particulates of
comparable sizes to dispersed product particles. Given this,
separation of the contaminant particles from the product particles
by filtration is generally ineffective. It is considered preferable
to adjust formulation and process parameters and materials to
minimize the generation of contaminants.
Attrition from the milling process can also result in chemical
alteration of the product dispersion. Many types of ceramic and
glass milling media contain metal oxides which release hydroxide
ions into the dispersion and increase product pH. Such pH changes
are undesirable since this can affect dispersion stability and
change milling performance.
A further disadvantage of attrition is the excessive wear of
milling media and mill components which can degrade milling
performance and increase manufacturing maintenance costs. Most
types of conventional media also require preconditioning to achieve
a steady rate of wear.
Problem to be Solved by the Invention
This invention is directed to a solution to the aforementioned
problems with preparing fine particle dispersions of
photographically useful compound.
Summary of the Invention
We have found that polymeric milling media is a viable alternative
to conventional ceramic, steel or glass media for the preparation
of compounds useful in imaging elements dispersions using
conventional media mill processes. The milling performance with
polymeric media is comparable to performance with conventional
media, despite the much lower media density of the polymeric media.
The levels of heavy metal contamination were found to be
unexpectedly low in dispersions prepared with polymeric media.
Photographic coating melts prepared from these dispersions were
found to contain a reduced number of large particulates normally
associated with physical coating defects in photographic film.
One aspect of this invention comprises a process for the
preparation of a solid particles of a compound useful in imaging
elements which comprises milling said compound in the presence of
milling media comprising a polymeric resin.
Another aspect of this invention comprises a photographic
dispersion comprising an aqueous medium having dispersed therein
solid particles of a compound useful in imaging elements having a
particle size of less than about 1 micron wherein the particles
have been prepared by milling said particles in the presence of a
milling media comprising a polymeric resin.
Advantageous Effect of the Invention
1. Polymeric milling media is suitable replacement for conventional
ceramic, glass or steel media and has comparable milling
performance to conventional media.
2. Given the absence of metal oxides and soluble salts, polymeric
media is preferable to conventional media since pH fluctuations and
chemical changes are minimized during milling. Such changes may
impair dispersion stability, hydrolyze certain solids and alter
milling performance.
3. Polymeric media results in much lower heavy metal
contamination.
4. The reduced density of polymeric media reduces power draw on the
mill and may reduce operating energy costs.
5. Reduced contamination with polymeric media can reduce
sensitometric and physical defects in film coatings which are
related to soluble or particle contaminants.
6. Reduced contamination with polymeric media improves both milling
media and milling components life.
7. Polymeric media are less sensitive to process conditions and may
provide improved scalability from pilot to production scale
processes.
8. Polymeric media may be less expensive than some types of ceramic
media formulated for wear resistance (e.g., yttria-stabilized
zirconium oxide media).
9. The reduced density of polymeric media improves the ease of
physical handling of the media and simplifies manufacturing
operations requiring heavy lifting by operators.
10. Contaminants from the polymeric media are likely to be
innocuous in photographic coatings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1-5 present the results obtained in Example 1 (below) in
graph form.
FIGS. 6-10 present the results obtained in Example 2 (below) in
graph form.
DETAILED DESCRIPTION OF THE INVENTION
This invention is based partly on the discovery that compounds
useful in imaging elements can be prepared in extremely fine
particles with reduced contamination levels by milling in the
presence of milling media comprising a polymeric resin. The term
"compounds useful in imaging elements" refers to compounds that can
be used in photographic elements, electrophotographic elements,
thermal transfer elements, and the like.
In the method of this invention a compound useful in imaging
elements is prepared in the form of particles by milling the
compound useful in imaging elements in the presence of a milling
media comprising a polymeric resin.
The milling media can comprise particles, preferably substantially
spherical in shape, e.g., beads, consisting essentially of the
polymeric resin. Alternatively, the milling media can comprise
particles comprising a core having a coating of the polymeric resin
adhered thereon.
In general, polymeric resins suitable for use herein are chemically
and physically inert, substantially free of metals, solvents and
monomers, and of sufficient hardness and friability to enable them
to avoid being chipped or crushed during milling. Suitable
polymeric resins include cross linked polystyrenes, such as
polystyrene cross linked with divinyl benzene, styrene copolymers,
polycarbonates, polyacetals, such as Delrin.TM., vinyl chloride
polymers and copolymers, polyurethanes, polyamides,
poly(tetrafluoroethylenes), e.g., Teflon.TM., and other
fluoropolymers, high density polyethylenes, polypropylenes,
cellulose ethers and esters such as cellulose acetate,
polyacrylates, such as
polymethylmethacrylate,polyhydroxymethacrylate and polyhydroxyethyl
acrylate, silicone containing polymers such as polysiloxanes and
the like. The polymer can be biodegradable. Exemplary biodegradable
polymers include poly(lactides), poly(glycolide), copolymers of
lactides and glycolide, polyanhydrides, poly(hydroxyethyl
methacrylate), poly(iminocarbonates), poly
(N-acylhydroxyproline)esters, poly (N-palmitoyl hydroxyproline
esters, ethylene-vinyl acetate copolymers, poly(orthoesters),
poly(caprolactones), and poly(phosphazenes).
The polymeric resin can have a density from 0.8 to 3.0 g/cm.sup.3.
Higher density resins are preferred as it is believed that these
provide more efficient particle size reduction.
The media can range in size from about 0.1 to about 3 mm. For fine
milling , the particles preferably are from 0.2 to 2 mm, more
preferably, 0.25 to 1 mm in size.
The core material can be selected from materials known to be useful
as milling media when fabricated as spheres or particles. Suitable
core materials include zirconium oxides (such as 95% zirconium
oxide stabilized with magnesia or yttrium), zirconium silicate,
glass stainless steel, titania, alumina, ferrite and the like.
Preferred core materials have a density greater than about 2.5
g/cm.sup.3. The selection of high density core materials is
believed to facilitate efficient particle size reduction.
Useful thicknesses of the polymer coating on the core are believed
to range from about 1 to 500 microns, although other thicknesses
outside this range may be useful in some applications. The
thickness of the polymer coating preferably is less than the
diameter of the core.
The cores can be coated with the polymer resin by techniques known
in the art. Suitable techniques include spray coating, fluidized
bed coating, and melt coating. Adhesion promoting or tie layers can
optionally be provided to improve the adhesion between the core
material and the resin coating. The adhesion of the polymer coating
to the core material can be enhanced by treating the core material
to adhesion promoting procedures, such as roughening the core
surface, corona discharge treatment, and the like.
The milling process can be a dry process, e.g., a dry roller
milling process or a wet process, i.e., wet-milling. In preferred
embodiments this invention is practiced in accordance with the
wet-milling process described in U.S. Pat. No. 5,145,684 and
European published application No. 498,482, the disclosures of
which are incorporated herein by reference. Thus, the wet milling
process can be practiced in conjunction with a liquid dispersion
medium and surface modifier such as described in these
publications. Useful liquid dispersion media include water, aqueous
salt solutions, ethanol, butanol, hexane, glycol and the like. The
surface modifier can be selected from known organic and inorganic
materials such as described is U.S. Pat. No. 5,145,684 and can be
present in an amount of 0.1-90%, preferably 1-80% by weight based
on the total weight of the dry particles.
In preferred embodiments, the compound useful in imaging elements
can be prepared in submicron or nanoparticulate particle size,
e.g., less than about 500 nanometers (nm). In certain embodiments,
particles having an average particle size of less than 300 nm have
been prepared in accordance with the present invention. It was
particularly surprising an unexpected that such fine particles
could be prepared at such low levels of contamination.
Milling can take place in any suitable milling mill. Suitable mills
include an airjet mill, a roller mill, a ball mill, a media mill an
attritor mill, a vibratory mill, a planetary mill, a sand mill, and
a bead mill. A high energy media mill is preferred when the milling
media consists essentially of the polymeric resin. The mill can
contain a rotation shaft.
The preferred proportions of the milling media, the compound useful
in imaging elements and the optional liquid dispersion medium and
surface modifier present in the milling vessel can vary with wide
limits and depends for example of the particular compound useful in
imaging elements selected, the size and density of the milling
media, the type of mill selected etc. The process can be carried
out in a continuous batch or semi-batch mode. In high energy media
mills, it can be desirable to fill 70-90% of the volume of the
milling chamber with milling media. On the other hand, in roller
mills, it frequently is desirable to leave the milling vessel up to
half filled with air, the remaining volume comprising the milling
media and the liquid dispersion media, if present. This permits a
cascading effect within the vessel on the rollers which permits
efficient milling. However, when foaming is a problem during wet
milling, the vessel can be completely filled with the liquid
dispersion medium.
The attrition time can vary widely and depends primarily upon the
particular photographically useful compound, mechanical means and
residence conditions selected, the initial and desired particle
size and so forth. For roller mills, processing times from several
days to weeks may be required. On the other hand residence times of
less than about 8 hours are generally required using high energy
media mills.
After attrition is completed, the milling media is separated from
the milled particulate product (in either a dry or liquid
dispersion form) using conventional separation techniques, such as
by filtration, sieving through a mesh screen and the like.
The process can be practiced with a wide variety of compounds
useful in imaging elements. In the case of dry milling the compound
useful in imaging elements should be capable of being formed into
solid particles. In the case of wet milling the compound useful in
imaging elements should be poorly soluble and dispersible in at
least one liquid medium. By "poorly soluble", it is meant that the
compound useful in imaging elements has a solubility in the liquid
dispersion medium, e.g., water, of less that about 10 mg/ml, and
preferably of less than about 1 mg/ml. The preferred liquid
dispersion medium is water. additionally, the invention can be
practiced with other liquid media.
In preferred embodiments of the invention the liquid dispersion
medium comprises water and a surfactant. The surfactant used can
be, for example, a polymeric dispersing aid described in copending
applications Ser. Nos. 228,971, 229,267, and 228,839, all filed on
Apr. 18, 1994, the disclosures of which are incorporated herein by
reference. Other surfactants that can be used include: ##STR1##
Suitable compounds useful in imaging elements include for example,
dye-forming couplers, development inhibitor release couplers
(DIR's), development inhibitor anchimeric release couplers
(DI(A)R's), masking couplers, filter dyes, thermal transfer dyes,
optical brighteners, nucleators, development accelerators, oxidized
developer scavengers, ultraviolet radiation absorbing compounds,
sensitizing dyes, development inhibitors, antifoggants, bleach
accelerators, magnetic particles, lubricants, matting agents,
etc.
Examples of such compounds can be found in Research Disclosure,
December 1989, Item 308,119 published by Kenneth Mason
Publications, Ltd., Dudley Annex, 12a North Street, Emsworth,
Hampshire P010 7DQ, England, Sections VII and VIII, which are
incorporated herein by reference, and in Research Disclosure,
November 1992, Item 34390 also published by Kenneth Mason
Publications and incorporated herein by reference.
Typical preferred compounds useful in imaging elements that can be
used in solid particle dispersions in accordance with this
invention are filter dyes, thermal transfer dyes and sensitizing
dyes, such as those described below. ##STR2## It is to be
understood that this list is representative only, and not meant to
be exclusive. In particularly preferred embodiments of the
invention, the compound useful in imaging elements is a sensitizing
dye, thermal transfer dye or filter dye.
In general, filter dyes that can be used in accordance with this
invention are those described in European patent applications EP
549,089 of Texter et al, and EP 430,180 and U.S. Pat. Nos.
4,803,150; 4,855,221; 4,857,446; 4,900,652; 4,900,653; 4,940,654;
4,948,717; 4,948,718; 4,950,586; 4,988,611; 4,994,356; 5,098,820;
5,213,956; 5,260,179; and 5,266,454; (the disclosures of which are
incorporated herein by reference).
In general, thermal transfer dyes that can be used in accordance
with this invention include anthraquinone dyes, e.g., Sumikaron
Violet RS.RTM. (product of Sumitomo Chemical Co., Ltd.), Dianix
Fast Violet 3R-FS.RTM. (product of Mitsubishi Chemical Industries,
Ltd.), and Kayalon Polyol Brilliant Blue N-BGM.RTM. and KST Black
146.RTM. (products of Nippon Kayaku Co., Ltd.); azo dyes such as
Kayalon Polyol Brilliant Blue BM.RTM., Kayalon Polyol Dark Blue
2BM.RTM., and KST Black KR.RTM. (products of Nippon Kayaku Co.,
Ltd.), Sumikaron Diazo Black 5G.RTM. (product of Sumitomo Chemical
Co., Ltd.), and Miktazol Black 5GH.RTM. (product of Mitsui Toatsu
Chemicals, Inc.); direct dyes such as Direct Dark Green B.RTM.
(product of Mitsubishi Chemical Industries, Ltd.) and Direct Brown
M.RTM. and Direct Fast Black D.RTM. (products of Nippon Kayaku Co.
Ltd.); acid dyes such as Kayanol Milling Cyanine 5R.RTM. (product
of Nippon Kayaku Co. Ltd.); basic dyes such as Sumiacryl Blue
6G.RTM. (product of Sumitomo Chemical Co., Ltd.), and Aizen
Malachite Green.RTM. (product of Hodogaya Chemical Co., Ltd.); or
any of the dyes disclosed in U.S. Pat. Nos. 4,541,830, 4,698,651,
4,695,287, 4,701,439, 4,757,046, 4,743,582, 4,769,360, and
4,753,922, the disclosures of which are hereby incorporated by
reference.
In general, sensitizing dyes that can be used in accordance with
this invention include cyanine dyes, merocyanine dyes, complex
cyanine dyes, complex merocyanine dyes, homopolar cyanine dyes,
hemicyanine dyes, styryl dyes, and hemioxonol dyes. Of these dyes,
cyanine dyes, merocyanine dyes and complex merocyanine dyes are
particularly useful.
Any conventionally utilized nuclei for cyanine dyes are applicable
to these dyes as basic heterocyclic nuclei. That is, a pyrroline
nucleus, an oxazoline nucleus, a thiazoline nucleus, a pyrrole
nucleus, an oxazole nucleus, a thiazole nucleus, a selenazole
nucleus, an imidazole nucleus, a tetrazole nucleus, a pyridine
nucleus, etc., and further, nuclei formed by condensing alicyclic
hydrocarbon rings with these nuclei and nuclei formed by condensing
aromatic hydrocarbon rings with these nuclei, that is, an
indolenine nucleus, a benzindolenine nucleus, an indole nucleus, a
benzoxazole nucleus, a naphthoxazole nucleus, a benzothiazole
nucleus, a naphthothiazole nucleus, a benzoselenazole nucleus, a
benzimidazole nucleus, a quinoline nucleus, etc., are appropriate.
The carbon atoms of these nuclei can also be substituted.
The merocyanine dyes and the complex merocyanine dyes that can be
employed contain 5- or 6-membered heterocyclic nuclei such as
pyrazolin-5-one nucleus, a thiohydantoin nucleus, a
2-thioxazolidin-2,4-dione nucleus, a thiazolidine-2,4-dione
nucleus, a rhodanine nucleus, a thiobarbituric acid nucleus, and
the like.
Solid particle dispersions of sensitizing dyes may be added to a
silver halide emulsion together with dyes which themselves do not
give rise to spectrally sensitizing effects but exhibit a
supersensitizing effect or materials which do not substantially
absorb visible light but exhibit a supersensitizing effect. For
example, aminostilbene compounds substituted with a
nitrogen-containing heterocyclic group (e.g., those described in
U.S. Pat. Nos. 2,933,390 and 3,635,721), aromatic organic
acid-formaldehyde condensates (e.g., those described in U.S. Pat.
No. 3,743,510), cadmium salts, azaindene compounds, and the like,
can be present.
The sensitizing dye may be added to an emulsion comprising silver
halide grains and, typically, a hydrophilic colloid at any time
prior to (e.g., during or after chemical sensitization) or
simultaneous with the coating of the emulsion on a photographic
support). The dye/silver halide emulsion may be mixed with a
dispersion of color image-forming coupler immediately before
coating or in advance of coating (for example, 2 hours). The
above-described sensitizing dyes can be used individually, or may
be used in combination, e.g. to also provide the silver halide with
additional sensitivity to wavelengths of light outside that
provided by one dye or to supersensitize the silver halide.
The dispersions of this invention can be used to prepare
photographic elements. In preferred embodiments of this invention,
a color photographic element comprises at least one layer
comprising a dispersion of this invention. In addition to the
dispersion of this invention, the photographic element comprises
other components typically used in photographic elements.
The dispersions of the invention can be used in any of the ways and
in any of the combinations known in the art. Typically, the
invention dispersions are incorporated in a silver halide emulsion
and the emulsion coated as a layer on a support to form part of a
photographic element.
The photographic elements can be single color elements or
multicolor elements. Multicolor elements contain image dye-forming
units sensitive to each of the three primary regions of the
spectrum. Each unit can comprise a single emulsion layer or
multiple emulsion layers sensitive to a given region of the
spectrum. The layers of the element, including the layers of the
image-forming units, can be arranged in various orders as known in
the art. In an alternative format, the emulsions sensitive to each
of the three primary regions of the spectrum can be disposed as a
single segmented layer.
A typical multicolor photographic element comprises a support
bearing a cyan dye image-forming unit comprised of at least one
red-sensitive silver halide emulsion layer having associated
therewith at least one cyan dye-forming coupler, a magenta dye
image-forming unit comprising at least one green-sensitive silver
halide emulsion layer having associated therewith at least one
magenta dye-forming coupler, and a yellow dye image-forming unit
comprising at least one blue-sensitive silver halide emulsion layer
having associated therewith at least one yellow dye-forming
coupler. The element can contain additional layers, such as filter
layers, interlayers, overcoat layers, subbing layers, and the
like.
If desired, the photographic element can be used in conjunction
with an applied magnetic layer as described in Research Disclosure,
November 1992, Item 34390 published by Kenneth Mason Publications,
Ltd., Dudley Annex, 12a North Street, Emsworth, Hampshire P010 7DQ,
ENGLAND.
In the following discussion of suitable materials for use in the
dispersions and elements of this invention, reference will be made
to Research Disclosure, December 1989, Item 308119, available as
described above, which will be identified hereafter by the term
"Research Disclosure." The contents of the Research Disclosure,
including the patents and publications referenced therein, are
incorporated herein by reference, and the Sections hereafter
referred to are Sections of the Research Disclosure.
The silver halide emulsions employed in the photographic elements
of this invention can be either negative-working or
positive-working. Suitable emulsions and their preparation as well
as methods of chemical and spectral sensitization are described in
Sections I through IV. Color materials and development modifiers
are described in Sections V and XXI. Vehicles are described in
Section IX, and various additives such as brighteners,
antifoggants, stabilizers, light absorbing and scattering
materials, hardeners, coating aids, plasticizers, lubricants and
matting agents are described , for example, in Sections V, VI,
VIII, X, XI, XII, and XVI. Manufacturing methods are described in
Sections XIV and XV, other layers and supports in Sections XIII and
XVII, processing methods and agents in Sections XIX and XX, and
exposure alternatives in Section XVIII.
Coupling-off groups are well known in the art. Such groups can
determine the chemical equivalency of a coupler, i.e., whether it
is a 2-equivalent or a 4-equivalent coupler, or modify the
reactivity of the coupler. Such groups can advantageously affect
the layer in which the coupler is coated, or other layers in the
photographic recording material, by performing, after release from
the coupler, functions such as dye formation, dye hue adjustment,
development acceleration or inhibition, bleach acceleration or
inhibition, electron transfer facilitation, color correction and
the like.
The presence of hydrogen at the coupling site provides a
4-equivalent coupler, and the presence of another coupling-off
group usually provides a 2-equivalent coupler. Representative
classes of such coupling-off groups include, for example, chloro,
alkoxy, aryloxy, hetero-oxy, sulfonyloxy, acyloxy, acyl,
heterocyclyl, sulfonamido, mercaptotetrazole, benzothiazole,
mercaptopropionic acid, phosphonyloxy, arylthio, and arylazo. These
coupling-off groups are described in the art, for example, in U.S.
Pat. Nos. 2,455,169, 3,227,551, 3,432,521, 3,476,563, 3,617,291,
3,880,661, 4,052,212 and 4,134,766; and in U.K. Patents and
published application Nos. 1,466,728, 1,531,927, 1,533,039,
2,006,755A and 2,017,704A, the disclosures of which are
incorporated herein by reference.
Image dye-forming couplers may be included in the element such as
couplers that form cyan dyes upon reaction with oxidized color
developing agents which are described in such representative
patents and publications as: U.S. Pat. Nos. 2,772,162, 2,895,826,
3,002,836, 3,034,892, 2,474,293, 2,423,730, 2,367,531, 3,041,236,
4,883,746 and "Farbkuppler-eine LiteratureUbersicht," published in
Agfa Mitteilungen, Band III, pp. 156-175 (1961). Preferably such
couplers are phenols and naphthols that form cyan dyes on reaction
with oxidized color developing agent.
Couplers that form magenta dyes upon reaction with oxidized color
developing agent are described in such representative patents and
publications as: U.S. Pat. Nos. 2,600,788, 2,369,489, 2,343,703,
2,311,082, 3,152,896, 3,519,429, 3,062,653, 2,908,573 and
"Farbkuppler-eine LiteratureUbersicht," published in Agfa
Mitteilungen, Band III, pp. 126-156 (1961). Preferably such
couplers are pyrazolones, pyrazolotriazoles, or
pyrazolobenzimidazoles that form magenta dyes upon reaction with
oxidized color developing agents.
Couplers that form yellow dyes upon reaction with oxidized and
color developing agent are described in such representative patents
and publications as: U.S. Pat. Nos. 2,875,057, 2,407,210,
3,265,506, 2,298,443, 3,048,194, 3,447,928 and "Farbkuppler-eine
LiteratureUbersicht," published in Agfa Mitteilungen, Band III, pp.
112-126 (1961). Such couplers are typically open chain
ketomethylene compounds.
It may be useful to use a combination of couplers any of which may
contain known ballasts or coupling-off groups such as those
described in U.S. Pat. Nos. 4,301,235; 4,853,319 and 4,351,897. The
coupler may also be used in association with "wrong" colored
couplers (e.g. to adjust levels of interlayer correction) and, in
color negative applications, with masking couplers such as those
described in EP 213.490; Japanese Published Application 58-172,647;
U.S. Pat. No. 2,983,608; German Application DE 2,706,117C; U.K.
Patent 1,530,272; Japanese Application A-113935; U.S. Pat. Nos.
4,070,191 and 4,273,861; and German Application DE 2,643,965. The
masking couplers may be shifted or blocked.
The invention dispersions may also be used in association with
materials that accelerate or otherwise modify the processing steps
e.g. of bleaching or fixing to improve the quality of the image.
Bleach accelerator releasing couplers such as those described in EP
193,389; EP 301,477; U.S. Pat. Nos. 4,163,669; 4,865,956; and
4,923,784, may be useful. Also contemplated is use of the
compositions in association with nucleating agents, development
accelerators or their precursors (UK Patent 2,097,140; U.K. Patent
2,131,188); electron transfer agents (U.S. Pat. Nos. 4,859,578;
4,912,025); antifogging and anti color-mixing agents such as
derivatives of hydroquinones, aminophenols, amines, gallic acid;
catechol; ascorbic acid; hydrazides; sulfonamidophenols; and non
color-forming couplers.
For example, in a color negative element, the dispersions of the
invention may replace or supplement the materials of an element
comprising a support bearing the following layers from top to
bottom:
(1) one or more overcoat layers containing ultraviolet
absorber(s);
(2) a two-coat yellow pack with a fast yellow layer containing
"Coupler 1": Benzoic acid,
4-chloro-3-((2-(4-ethoxy-2,5-dioxo-3-(phenylmethyl)-1-imidazolidinyl)-3-(4
-methoxyphenyl)-1,3-dioxopropyl)amino)-, dodecyl ester and a slow
yellow layer containing the same compound together with "Coupler
2": Propanoic acid,
2-[[5-[[4-[2-[[[2,4-bis(1,1-dimethylpropyl)phenoxy]acetyl]amino]-5-[(2,2,3
,3,4,4,4-heptafluoro-1-oxobutyl)amino]-4-hydroxyphenoxy]-2,3-dihydroxy-6-[(
propylamino)carbonyl ]phenyl]thio]-1,3,4-thiadiazol-2-yl]thio]-,
methyl ester and "Coupler 3": 1-((dodecyloxy)carbonyl)
ethyl(3-chloro-4-((3-(2-chloro-4-((1-tridecanoylethoxy)
carbonyl)anilino)-3-oxo-2-((4)(5)(6)-(phenoxycarbonyl)-1H-benzotriazol-1-y
l)propanoyl)amino))benzoate;
(3) an interlayer containing fine metallic silver;
(4) a triple-coat magenta pack with a fast magenta layer containing
"Coupler 4": Benzamide,
3-((2-(2,4-bis(1,1-dimethylpropyl)phenoxy)-1-oxobutyl)amino)-N-(4,5-dihydr
o-5-oxo-1-(2,4,6-trichlorophenyl)-1H-pyrazol-3-yl)-,"Coupler 5":
Benzamide,
3-((2-(2,4-bis(1,1-dimethylpropyl)phenoxy)-1-oxobutyl)amino)-N-(4',5'-dihy
dro-5'-oxo-1'-(2,4,6-trichlorophenyl)
(1,4'-bi-1H-pyrazol)-3'-yl)-,"Coupler 6": Carbamic acid,
(6-(((3-(dodecyloxy)propyl)
amino)carbonyl)-5-hydroxy-1-naphthalenyl)-, 2-methylpropyl ester ,
"Coupler 7": Acetic acid, ((2-((3-(((3-(dodecyloxy)propyl)amino)
carbonyl)-4-hydroxy-8-(((2-methylpropoxy)carbonyl)
amino)-1-naphthalenyl)oxy )ethyl)thio)-, and "Coupler 8" Benzamide,
3-((2-(2,4-bis(1,1-dimethylpropyl)
phenoxy)-1-oxobutyl)amino)-N-(4,5-dihydro-4-((4-methoxyphenyl)
azo)-5-oxo-1-(2,4,6-trichlorophenyl)-1H-pyrazol-3-yl)-; a
mid-magenta layer and a slow magenta layer each containing "Coupler
9": a ternary copolymer containing by weight in the ratio 1:1:2
2-Propenoic acid butyl ester, styrene, and
N-[1-(2,4,6-trichlorophenyl)-4,5-dihydro-5-oxo-1H-pyrazol-3-yl]-2-methyl-2
-propenamide; and "Coupler 10": Tetradecanamide,
N-(4-chloro-3-((4-((4-((2,2-dimethyl-1-oxopropyl)
amino)phenyl)azo)-4,5-dihydro-5-oxo-1(2,4,6-trichlorophenyl)-1H-pyrazol-3-
yl)amino)phenyl)-, in addition to Couplers 3 and 8; (5) an
interlayer; (6) a triple-coat cyan pack with a fast cyan layer
containing Couplers 6 and 7; a mid-cyan containing Coupler 6 and
"Coupler 11": 2,7-Naphthalenedisulfonic acid,
5-(acetylamino)-3-((4-(2-((3-(((3-(2,4-bis(1,1-dimethylpropyl)phenoxy)
propyl)amino)carbonyl)-4-hydroxy-1-naphthalenyl)
oxy)ethoxy)phenyl)azo)-4-hydroxy-, disodium salt; and a slow cyan
layer containing Couplers 2 and 6;
(7) an undercoat layer containing Coupler 8; and
(8) an antihalation layer.
In a color paper format, the dispersions of the invention may
replace or supplement the materials of an element comprising a
support bearing the following layers from top to bottom:
(1) one or more overcoats;
(2) a cyan layer containing "Coupler 1": Butanamide,
2-(2,4-bis(1,1-dimethylpropyl)phenoxy)-N-(3,5-dichloro-2-hydroxy-4-methylp
henyl)-, "Coupler 2": Acetamide,
2-(2,4-bis(1,1-dimethylpropyl)phenoxy)-N-(3,5-dichloro-2-hydroxy-4-,
and UV Stabilizers: Phenol,
2-(5-chloro-2H-benzotriazol-2-yl)-4,6-bis(1,1-dimethylethyl)-;
Phenol, 2-(2H-benzotriazol-2-yl)-4-(1,1-dimethylethyl)-;Phenol,
2-(2H-benzotriazol-2-yl)-4-(1,1-dimethylethyl)-6-(1-methylpropyl)-;
and Phenol,
2-(2H-benzotriazol-2-yl)-4,6-bis(1,1-dimethylpropyl)-and a
poly(t-butylacrylamide) dye stabilizer;
(3) an interlayer;
(4) a magenta layer containing "Coupler 3": Octanamide,
2-[2,4-bis(1,1-dimethylpropyl)phenoxy]-N-[2-(7-chloro-6-methyl-1H-pyrazolo
[1,5-b][1,2,4]triazol-2-yl)propyl]- together with
1,1'-Spirobi(1H-indene),
2,2',3,3'-tetrahydro-3,3,3',3'-tetramethyl-5,5',6,6'-tetrapropoxy-;
(5) an interlayer; and
(6) a yellow layer containing "Coupler 4":
1-Imidazolidineacetamide,
N-(5-((2-(2,4-bis(1,1-dimethylpropyl)phenoxy)-1-oxobutyl)amino)-2-chloroph
enyl)-.alpha.-(2,2-dimethyl-1-oxopropyl)-4-ethoxy-2,5-dioxo-3-(phenylmethyl
)-.
In a reversal format, the dispersions of the invention may replace
or supplement the materials of an element comprising a support
bearing the following layers from top to bottom:
(1) one or more overcoat layers;
(2) a nonsensitized silver halide containing layer;
(3) a triple-coat yellow layer pack with a fast yellow layer
containing "Coupler 1": Benzoic acid,
4-(1-(((2-chloro-5-((dodecylsulfonyl)amino)phenyl)
amino)carbonyl)-3,3-dimethyl-2-oxobutoxy)-, 1-methylethyl ester; a
mid yellow layer containing Coupler 1 and "Coupler 2": Benzoic
acid,
4-chloro-3-[[2-[4-ethoxy-2,5-dioxo-3-(phenylmethyl)-1-imidazolidinyl]-4,4-
dimethyl-1,3-dioxopentyl]amino]-, dodecylester; and a slow yellow
layer also containing Coupler 2;
(4) an interlayer;
(5) a layer of fine-grained silver;
(6) an interlayer;
(7) a triple-coated magenta pack with a fast magenta layer
containing "Coupler 3": 2-Propenoic acid, butyl ester, polymer with
N-[1-(2,5-dichlorophenyl)-4,5-dihydro-5-oxo-1H-pyrazol-3-yl]-2-methyl-2pro
penamide; "Coupler 4": Benzamide,
3-((2-(2,4-bis(1,1-dimethylpropyl)phenoxy)-1-oxobutyl)amino)-N-(4,5-dihydr
o-5-oxo-1-(2,4,6-trichlorophenyl)-1H-pyrazol-3-yl)-; and "Coupler
5": Benzamide,
3-(((2,4bis(1,1-dimethylpropyl)phenoxy)acetyl)amino)-N-(4,5-dihydro-5-oxo-
1-(2,4,6-trichlorophenyl)-1H-pyrazol-3-yl)-; and containing the
stabilizer 1,1'-Spirobi(1H-indene),
2,2',3,3'-tetrahydro-3,3,3',3'-tetramethyl-5,5',6,6'-tetrapropoxy-;
and in the slow magenta layer Couplers 4 and 5 with the same
stabilizer;
(8) one or more interlayers possibly including fine-grained
nonsensitized silver halide;
(9) a triple-coated cyan pack with a fast cyan layer containing
"Coupler 6": Tetradecanamide,
2-(2-cyanophenoxy)-N-(4-((2,2,3,3,4,4,4-heptafluoro-1-oxobutyl)amino)-3-hy
droxyphenyl)-; a mid cyan containing"Coupler 7": Butanamide,
N-(4-((2-(2,4-bis(1,1-dimethylpropyl)phenoxy)-1-oxobutyl)amino)-2-hydroxyp
henyl)-2,2,3,3,4,4,4-heptafluoro- and "Coupler 8": Hexanamide,
2-(2,4-bis (1,1-dimethylpropyl)
phenoxy)-N-(4-((2,2,3,3,4,4,4-heptafluoro-1-oxobutyl)amino)-3-hydroxypheny
l)-;
(10) one or more interlayers possibly including fine-grained
nonsensitized silver halide; and
(11) an antihalation layer.
The invention dispersions may also be used in combination with
filter dye layers comprising colloidal silver sol or yellow, cyan,
and/or magenta filter dyes, either as oil-in-water dispersions,
latex dispersions or as solid particle dispersions. Additionally,
they may be used with "smearing" couplers (e.g. as described in
U.S. Pat. No. 4,366,237; EP 96,570; U.S. Pat. Nos. 4,420,556; and
4,543,323.) Also, the compositions may be blocked or coated in
protected form as described, for example, in Japanese Application
61/258,249 or U.S. Pat. No. 5,019,492.
The invention dispersions may further be used in combination with
image-modifying compounds such as "Developer Inhibitor-Releasing"
compounds (DIR's). DIR's useful in conjunction with the
compositions of the invention are known in the art and examples are
described in U.S. Pat. Nos. 3,137,578; 3,148,022; 3,148,062;
3,227,554; 3,384,657; 3,379,529; 3,615,506; 3,617,291; 3,620,746;
3,701,783; 3,733,201; 4,049,455; 4,095,984; 4,126,459; 4,149,886;
4,150,228; 4,211,562; 4,248,962; 4,259,437; 4,362,878; 4,409,323;
4,477,563; 4,782,012; 4,962,018; 4,500,634; 4,579,816; 4,607,004;
4,618,571; 4,678,739; 4,746,600; 4,746,601; 4,791,049; 4,857,447;
4,865,959; 4,880,342; 4,886,736; 4,937,179; 4,946,767; 4,948,716;
4,952,485; 4,956,269; 4,959,299; 4,966,835; 4,985,336 as well as in
patent publications GB 1,560,240 ; GB 2,007,662; GB 2,032,914; GB
2,099,167; DE 2,842,063, DE 2,937,127; DE 3,636,824; DE 3,644,416
as well as the following European Patent Publications: 272,573;
335,319; 336,411; 346, 899; 362, 870; 365,252; 365,346; 373,382;
376,212; 377,463; 378,236; 384,670; 396,486; 401,612; 401,613.
Such compounds are also disclosed in "Developer-Inhibitor-Releasing
(DIR) Couplers for Color Photography," C. R. Barr, J. R. Thirtle
and P. W. Vittum in Photographic Science and Engineering, Vol. 13,
p. 174 (1969), incorporated herein by reference. Generally, the
developer inhibitor-releasing (DIR) couplers include a coupler
moiety and an inhibitor coupling-off moiety (IN). The
inhibitor-releasing couplers may be of the time-delayed type (DIAR
couplers) which also include a timing moiety or chemical switch
which produces a delayed release of inhibitor. Examples of typical
inhibitor moieties are: oxazoles, thiazoles, diazoles, triazoles,
oxadiazoles, thiadiazoles, oxathiazoles, thiatriazoles,
benzotriazoles, tetrazoles, benzimidazoles, indazoles,
isoindazoles, mercaptotetrazoles, selenotetrazoles,
mercaptobenzothiazoles, selenobenzothiazoles, mercaptobenzoxazoles,
selenobenzoxazoles, mercaptobenzimidazoles, selenobenzimidazoles,
benzodiazoles, mercaptooxazoles, mercaptothiadiazoles,
mercaptothiazoles, mercaptotriazoles, mercaptooxadiazoles,
mercaptodiazoles, mercaptooxathiazoles, telleurotetrazoles or
benzisodiazoles. In a preferred embodiment, the inhibitor moiety or
group is selected from the following formulas: ##STR3## wherein
R.sub.I is selected from the group consisting of straight and
branched alkyls of from 1 to about 8 carbon atoms, benzyl, phenyl,
and alkoxy groups and such groups containing none, one or more than
one such substituent; R.sub.II is selected from R.sub.I and
--SR.sub.I ; R.sub.III is a straight or branched alkyl group of
from 1 to about 5 carbon atoms and m is from 1 to 3; and R.sub.IV
is selected from the group consisting of hydrogen, halogens and
alkoxy, phenyl and carbonamido groups, --COOR.sub.V and
--NHCOOR.sub.V wherein R.sub.V is selected from substituted and
unsubstituted alkyl and aryl groups.
Although it is typical that the coupler moiety included in the
developer inhibitor-releasing coupler forms an image dye
corresponding to the layer in which it is located, it may also form
a different color as one associated with a different film layer. It
may also be useful that the coupler moiety included in the
developer inhibitor-releasing coupler forms colorless products
and/or products that wash out of the photographic material during
processing (so-called "universal" couplers).
As mentioned, the developer inhibitor-releasing coupler may include
a timing group which produces the time-delayed release of the
inhibitor group such as groups utilizing the cleavage reaction of a
hemiacetal (U.S. Pat. No. 4,146,396, Japanese Applications
60-249148; 60-249149); groups using an intramolecular nucleophilic
substitution reaction (U.S. Pat. No. 4,248,962); groups utilizing
an electron transfer reaction along a conjugated system (U.S. Pat.
Nos. 4,409,323; 4,421,845; Japanese Applications 57-188035;
58-98728; 58-209736; 58-209738) groups utilizing ester hydrolysis
(German Patent Application (OLS) No. 2,626,315; groups utilizing
the cleavage of imino ketals (U.S. Pat. No. 4,546,073); groups that
function as a coupler or reducing agent after the coupler reaction
(U.S. Pat. No. 4,438,193; U.S. Pat. No. 4,618,571) and groups that
combine the features describe above. It is typical that the timing
group or moiety is of one of the formulas: ##STR4## wherein IN is
the inhibitor moiety, Z is selected from the group consisting of
nitro, cyano, alkylsulfonyl; sulfamoyl (--SO.sub.2 NR.sub.2); and
sulfonamido (--NRSO.sub.2 R) groups; n is 0 or 1; and R.sub.VI is
selected from the group consisting of substituted and unsubstituted
alkyl and phenyl groups. The oxygen atom of each timing group is
bonded to the coupling-off position of the respective coupler
moiety of the DIAR.
Suitable developer inhibitor-releasing couplers for use in the
present invention include, but are not limited to, the following:
##STR5##
It is also contemplated that the concepts of the present invention
may be employed to obtain reflection color prints as described in
Research Disclosure, November 1979, Item 18716, available from
Kenneth Mason Publications, Ltd, Dudley Annex, 12a North Street,
Emsworth, Hampshire P0101 7DQ, England, incorporated herein by
reference. Dispersions of the invention may be coated on pH
adjusted support as described in U.S. Pat. No. 4,917,994; with
epoxy solvents (EP 0 164 961); with nickel complex stabilizers
(U.S. Pat. Nos. 4,346,165; 4,540,653 and 4,906,559 for example);
with ballasted chelating agents such as those in U.S. Pat. No.
4,994,359 to reduce sensitivity to polyvalent cations such as
calcium; and with stain reducing compounds such as described in
U.S. Pat. No. 5,068,171. Other compounds useful in combination with
the invention are disclosed in Japanese Published Applications
described in Derwent Abstracts having accession numbers as follows:
90-072,629, 90-072,630; 90-072,631; 90-072,632; 90-072,633;
90-072,634; 90-077,822; 90-078,229; 90-078,230; 90-079,336;
90-079,337; 90-079,338; 90-079,690; 90-079,691; 90-080,487;
90-080,488; 90-080,489; 90-080,490; 90-080,491; 90-080,492;
90-080,494; 90-085,928; 90-086,669; 90-086,670; 90-087,360;
90-087,361; 90-087,362; 90-087,363; 90-087,364; 90-088,097;
90-093,662; 90-093,663; 90-093,664; 90-093,665; 90-093,666;
90-093,668; 90-094,055; 90-094,056; 90-103,409; 83-62,586;
83-09,959.
Especially useful in this invention are tabular grain silver halide
emulsions. Specifically contemplated tabular grain emulsions are
those in which greater than 50 percent of the total projected area
of the emulsion grains are accounted for by tabular grains having a
thickness of less than 0.3 micron (0.5 micron for blue sensitive
emulsion) and an average tabularity (T) of greater than 25
(preferably greater than 100), where the term "tabularity" is
employed in its art recognized usage as
where
ECD is the average equivalent circular diameter of the tabular
grains in microns and
t is the average thickness in microns of the tabular grains.
The average useful ECD of photographic emulsions can range up to
about 10 microns, although in practice emulsion ECD's seldom exceed
about 4 microns. Since both photographic speed and granularity
increase with increasing ECD's, it is generally preferred to employ
the smallest tabular grain ECD's compatible with achieving aim
speed requirements.
Emulsion tabularity increases markedly with reductions in tabular
grain thickness. It is generally preferred that aim tabular grain
projected areas be satisfied by thin (t<0.2 micron) tabular
grains. To achieve the lowest levels of granularity it is preferred
that aim tabular grain projected areas be satisfied with ultrathin
(t<0.06 micron) tabular grains. Tabular grain thicknesses
typically range down to about 0.02 micron. However, still lower
tabular grain thicknesses are contemplated. For example, Daubendiek
et al U.S. Pat. No. 4,672,027 reports a 3 mole percent iodide
tabular grain silver bromoiodide emulsion having a grain thickness
of 0.017 micron.
As noted above tabular grains of less than the specified thickness
account for at least 50 percent of the total grain projected area
of the emulsion. To maximize the advantages of high tabularity it
is generally preferred that tabular grains satisfying the stated
thickness criterion account for the highest conveniently attainable
percentage of the total grain projected area of the emulsion. For
example, in preferred emulsions, tabular grains satisfying the
stated thickness criteria above account for at least 70 percent of
the total grain projected area. In the highest performance tabular
grain emulsions, tabular grains satisfying the thickness criteria
above account for at least 90 percent of total grain projected
area.
Suitable tabular grain emulsions can be selected from among a
variety of conventional teachings, such as those of the following:
Research Disclosure, Item 22534, January 1983, published by Kenneth
Mason Publications, Ltd., Emsworth, Hampshire P010 7DD, England;
U.S. Pat. Nos. 4,439,520; 4,414,310; 4,433,048; 4,643,966;
4,647,528; 4,665,012; 4,672,027; 4,678,745; 4,693,964; 4,713,320;
4,722,886; 4,755,456; 4,775,617; 4,797,354; 4,801,522; 4,806,461;
4,835,095; 4,853,322; 4,914,014; 4,962,015; 4,985,350; 5,061,069
and 5,061,616. In addition, use of [100] silver chloride emulsions
as described in EP 534,395 are specifically contemplated.
The emulsions can be surface-sensitive emulsions, i.e., emulsions
that form latent images primarily on the surfaces of the silver
halide grains, or the emulsions can form internal latent images
predominantly in the interior of the silver halide grains. The
emulsions can be negative-working emulsions, such as
surface-sensitive emulsions or unfogged internal latent
image-forming emulsions, or direct-positive emulsions of the
unfogged, internal latent image-forming type, which are
positive-working when development is conducted with uniform light
exposure or in the presence of a nucleating agent.
Photographic elements can be exposed to actinic radiation,
typically in the visible region of the spectrum, to form a latent
image and can then be processed to form a visible dye image.
Processing to form a visible dye image includes the step of
contacting the element with a color developing agent to reduce
developable silver halide and oxidize the color developing agent.
Oxidized color developing agent in turn reacts with the coupler to
yield a dye.
With negative-working silver halide, the processing step described
above provides a negative image. The described elements can be
processed in the known C-41 color process as described in The
British Journal of Photography Annual of 1988, pages 191-198. Where
applicable, the element may be processed in accordance with color
print processes such a the RA-4 process of Eastman Kodak Company as
described in the British Journal of Photography Annual of 1988, Pp
198-199. To provide a positive (or reversal) image, the color
development step can be preceded by development with a
non-chromogenic developing agent to develop exposed silver halide,
but not form dye, and followed by uniformly fogging the element to
render unexposed silver halide developable. Alternatively, a direct
positive emulsion can be employed to obtain a positive image.
Preferred color developing agents are p-phenylenediamines such
as:
4-amino-N,N-diethylaniline hydrochloride,
4-amino-3-methyl-N,N-diethylaniline hydrochloride,
4-amino-3-methyl-N-ethyl-N-(b-(methanesulfonamido) ethyl)aniline
sesquisulfate hydrate,
4-amino-3-methyl-N-ethyl-N-(b-hydroxyethyl)aniline sulfate,
4-amino-3-b-(methanesulfonamido)ethyl-N,N-diethylaniline
hydrochloride and
4-amino-N-ethyl-N-(2-methoxyethyl)-m-toluidine di-p-toluene
sulfonic acid.
Development is usually followed by the conventional steps of
bleaching, fixing, or bleach-fixing, to remove silver or silver
halide, washing, and drying.
The following examples illustrate the process of this
invention.
Polymeric Media Preparation
Inhibitor is removed from a mixture of 9.72 kg of styrene and 38.88
kg divinylbenzene by slurrying with 1.95 kg of basic aluminum oxide
(55% grade from Dow Chemical Co.) for 15 minutes followed by
filtering off the aluminum oxide. 240 gm of
2,2'-azobis(2,4-dimethylvaleronitrile) sold as Vazo 52 by the
Dupont Company and 240 gm of 2,2'-azobis(2methylpentanenitrile)
sold as Perkadox AMBN by AKZO Chemical are then dissolved in this
uninhibited monomer mixture. In a separate vessel is added 57 kg of
demineralized water to which is added 81 gm of
poly(2-methylaminoethanol adipate), and 72 gm of Nalcoag 2329, a
40% colloidal suspension of silica sold by Nalco Chemical Company.
The uninhibited monomers are added to the aqueous phase and stirred
to form a crude emulsion. This is passed twice through a Crepaco
homogenizer operated at 5,000 psi. To this is added a solution of
600 gm of polyvinyl alcohol sold by Air Products Company under the
trade designation Vinol 523 dissolved in 12.9 kg of demineralized
water. The mixture is heated to 45.degree. C. for 16 hours followed
by heating to 85.degree. C. for 4 hours. The resulting solid
particles are sieved between 18 and 52 mesh. 9 kg of this damp cake
is then purified by reslurrying in 9 gal of acetone at 56.degree.
C. The acetone washing is repeated for a total of three reslurries.
The acetone damp cake is then added to a mixture of 34.8 kg
demineralized water, 11.4 kg methanol and 2.8 kg of 50% NaOH and
held at room temperature overnight to remove the silica. The beads
are washed with demineralized water to a neutral pH and dried under
vacuum for 3 days at 50.degree. C.
Example 1
Three separate 6.0 kg of a magenta solid particle filter dye
dispersions were prepared in a Netzsch LME-4 media mill with the
following formulation:
______________________________________ dye 8% surfactant 0.96%
water 91.04% ______________________________________
The dye used has the following structural formula: ##STR6## A
conventional approach was used for all variations which included
the following steps:
1. mixing all ingredients to form a premix slurry
2. adding the milling media to the mill milling chamber
3. pumping the premix through the mill milling chamber in a
recirculation mode while the mill milling impellers are agitated at
the desired rpm
4. discharging the dispersion from the mill after milling is
complete
In samples 1 and 2, zirconium silicate media was used and in batch
3 polystyrene media was used.
______________________________________ Sample Media Load RPM Media
Type ______________________________________ 1 90% 2300 zirconium
silicate (0.6-0.8 mm) 2 80% 2100 zirconium silicate (0.6-0.8 mm) 3
80% 2100 SDy20 polystyrene (0.4-5 mm)
______________________________________
Aliquots were extracted at various residence times during milling
and a variety of analytical measurements were made. These are
tabulated in Table I.
TABLE I
__________________________________________________________________________
Disc residence Centrifuge CASS Zr Fe Si Sample time (min) (% <
0.1 mm) (L/mol-cm) pH (ppm) (ppm) (ppm)
__________________________________________________________________________
1a 31 36.8 41135 3.96 780 42 270 1b 75 50 43208 4.28 2000 88 640 1c
180 54.4 43891 4.41 4200 190 1400 2a 44 38.7 42169 4.1 420 23 150
2b 111 51.1 44832 4.35 1200 62 350 2c 189 56 45802 4.51 1700 110
540 3a 31.2 36.1 41251 3.55 1.5 0.87 <10 3b 74.9 49.8 42918 3.72
1.6 1.5 <10 3c 184.1 53.6 43723 3.84 1.9 5 <10
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The dispersion particle size was measured by Disc Centrifuge, and
the results are reported as the percentage of particles below 0.1
.mu.m. CASS Emax corresponds to the coefficient of molar extinction
of the dye (i.e. the covering power). Contamination from zirconium,
iron and silicon from the milling media and stainless steel mill
components were measured inductively Coupled Plasma Spectroscopy
(ICP).
Results
FIG. 1 shows particle size reduction as a function of residence
time, which is an indicator of milling efficiency. As shown, under
similar milling conditions of RPM and % Media Load, the size
reduction efficiency is comparable between zirconium silicate
(sample 2) and polystyrene (sample 3) media. Likewise, FIG. 2 shows
that covering power is comparable. FIG. 3 shows lower pH and a
reduced level of increase in pH during milling for polystyrene
media. This is considered advantageous since dispersion stability
may be compromised as pH changes. FIGS. 4 and 5 show contamination
levels for zirconium and iron. Polystyrene media results in
significantly less heavy metal contamination.
Example 2
In a similar experiment, an orange filter dye dispersion was
prepared in a 0.3 Liter Dyno-Mill at 40% dye, 4% surfactant, and
66% water. Again, three dispersions were prepared by conventional
means with the following variations:
______________________________________ Sample % Media Load RPM
Media ______________________________________ 4 90% 3200 zirconium
silicate 5 90% 3200 zirconium silicate 6 90% 3200 polystyrene
______________________________________
The dye used has the following structural formula: ##STR7##
Results
FIG. 6 shows particle size vs. residence time measured by Discrete
Wavelength Turbidimetry (DWT), confirming that the polystyrene
performs comparably to zirconium silicate. FIGS. 7 and 8 show that
spectral covering and off peak absorbance for these variations are
comparable. FIG. 9 shows that pH increase is reduced with polymeric
media. FIG. 10 shows that metals contamination is greatly
reduced.
The invention has been described in detail with particular
reference to preferred embodiments thereof, but it is to be
understood that variations and modifications can be effected within
the spirit and scope of the invention.
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